5 



coloured forked appendage just behind its head, which, when the creature is 

 alarmed, gives out a strongly scented fluid. Bonnet says ; " When I pressed 

 this caterpillar near its anterior part, it darted forth its horn as if it meant 

 to prick me with it, directing it towards my finger, but it withdrew it as soon 

 as I left off pressing it. This horn smelled strongly of fennel, and probably 

 is employed by the insect, by means of its powerful scent, to drive away the 

 flies and ichneumons that attack it. This remarkable V shaped scent 

 organ is situated at the anterior margin at the back of the second segment, 

 close to the head, from which, at first view, it seems to proceed. At 

 the bottom it is simple, but divided towards the middle, like the letter Y> 

 into two forks of a fleshy substance, which it can lengthen, as a snail does 

 its horns, to five times their ordinary extent, or retract them within the stalk 

 so as wholly to conceal them. Sometimes it protrudes one fork, keeping the 

 other retracted ; and often withdraws the whole apparatus for hours together 

 under the skin, and its place is only marked by two tawny coloured dots, so 

 that an ordinary spectator would not suspect the existence of such an instru- 

 ment." Moses Harris describes the caterpillar as being marked with black 

 transverse lines, in the same manner as the stripes of the zebra, on which 

 lines and stripes are spots of fine crimson. 



The chrysalis again is very pretty, especially when of its ordinary colour, 

 which is a lively green, shaded in some parts into bright yellow, but there is 

 a frequent variety marked only with various shades of brown and buff. In 

 shape it is angular, with the head slightly bifid. 



The first brood of the butterfly appears on the wing the middle of Ma} 7 , 

 according to Lewin. The female lays her eggs in ten or twelve days after, 

 and in a week's time the young caterpillars come forth. In six or seven days 

 they cast their first skin ; about the end of June they change their skin for 

 the fifth and last time ; and in six or seven days after this, they arrive at 

 full growth. They then prepare for their approaching metamorphosis by 

 fixing themselves with a strong belt of silk round the middle of their bod}', 

 and by the tail. In a day's time the chrysalis is complete, and this superb 

 butterfly comes forth in July following. The caterpillars from the eggs of 

 this brood are bred about the first week in August. After the usual shift- 

 ing of their skins they become full fed in the end of September, and change 

 to a chrysalis in a short time. In this state they remain through the winter, 

 and the butterflies are produced the following May. 



The chrysalides are most interesting objects to keep during the winter 

 months. As the spring advances, the colours of the butterfly begin to appear 

 faintly through their green envelope, and the pattern of the upper wings, 

 which only are visible, becomes at last distinctly perceptible, of course, in 



